Advance mechanism for a mine roof support assembly

Abstract

The invention relates to an advance mechanism for a roof support assembly constituted by a plurality of roof support units positioned side-by-side along, for example, a longwall face of a mineral mining working. The advance mechanism comprises a pair of hydraulic advance rams and a pair of resilient, generally parallel guide rods. The guide rods are interconnected at one end by means of a head-piece which is attachable to a conveyor extending along the longwall face. The other end of each guide rod is attached to a respective slide piece which is slidably guided on a respective guide rail which is attached to a floor girder of a roof support unit. The hydraulic advance rams are each pivotally attached to one of the slide pieces and to one of said floor girders. The guide rods are provided, adjacent said one end, with outwardly projecting alignment members each of which co-operates with one of said floor girders to align an associated roof support unit during its advance.

We claim: 
     
       1. An advance mechanism for a roof support assembly constituted by a plurality of roof support units positioned side-by-side along, for example, a longwall face of a mineral mining working, the advance mechanism comprising hydraulic advance ram means and a pair of resilient, generally parallel guide rods, the guide rods being interconnected at one end by means of a head-piece which is attachable to a conveyor extending along the longwall face, the other end of each guide rod being attached to a respective slide piece which is slidably guided on a respective guide rail which is attached to a floor girder of a roof support unit, the hydraulic advance ram means being pivotally attached to the guide rods and to said floor girders, wherein the guide rods are provided, adjacent said one end, with outwardly projecting alignment members each of which co-operates with one of said floor girders to align an associated roof support unit during its advance. 
     
     
       2. An advance mechanism according to claim 1, wherein the hydraulic advance ram means is constituted by a pair of hydraulic advance rams each of which is pivotally attached to the slide piece of a respective guide rod. 
     
     
       3. An advance mechanism according to claim 2, wherein each of the alignment members is constituted by an outwardly-bent portion of the respective guide rod. 
     
     
       4. An advance mechanism according to claim 1, wherein the guide rods are unconnected at said other ends. 
     
     
       5. An advance mechanism as claimed in any one of claims 1 to 4, wherein each of the guide rods is adjustably attached to the head-piece so as to extend therefrom by any one of a plurality of different distances. 
     
     
       6. A roof support assembly for use in a longwall face of a mineral mining working, the roof support assembly being constituted by a plurality of roof support units positioned side-by-side and means for advancing the roof support units towards the longwall face, each of the roof support units having at least one floor girder, the advance means being constituted by a plurality of advance mechanisms each of which comprises hydraulic advance ram means and a pair of resilient, generally parallel guide rods, the guide rods being interconnected at one end by means of a head-piece which is attachable to a conveyor extending along the longwall face, the other end of each guide rod being attached to a respective slide piece which is slidably guided on a respective guide rail which is attached to a respective floor girder, the hydraulic advance ram means being pivotally attached to the guide rods and to said floor girders, wherein the guide rods of each advance mechanism are provided, adjacent said one end, with outwardly projecting alignment members each of which co-operates with one of the floor girders associated with that advance mechanism to align the respective roof support unit during its advance. 
     
     
       7. A roof support assembly according to claim 6, wherein each advance mechanism is positioned between an adjacent pair of roof support units, the guide rails of that advance mechanism being fastened to the adjacent floor girders of that pair of roof support units. 
     
     
       8. A roof support assembly according to claim 6, wherein the two floor girders associated with a given advance mechanism are each provided with an alignment device which co-operates, during the final portion of the advance movement of the associated roof support unit, with a respective one of the alignment members of the guide rods of that advance mechanism. 
     
     
       9. A roof support assembly according to claim 8, wherein each alignment device has an alignment surface for sliding engagement with a complementary alignment surface on the corresponding alignment member, the alignment surfaces being inclined with respect to the direction of advance of the associated roof support unit. 
     
     
       10. A roof support assembly according to claim 8, wherein each alignment device and alignment member pair also constitutes a stop member. 
     
     
       11. A roof support assembly according to claim 8, wherein each alignment device is provided on the side of the respective floor girder part-away along that girder and adjacent to that end thereof which is nearer said one end of the associated guide rod. 
     
     
       12. A roof support assembly according to claim 11, wherein a further alignment device is provided on each floor girder, the further alignment devices being positioned at said ends thereof and serving to co-operate with the alignment members to provide initial guiding and aligning of the roof support units before said final portion of their advance. 
     
     
       13. A roof support assembly according to claim 8, wherein each floor girder is provided with an additional alignment device which co-operates with an additional alignment member provided on the associated slide piece. 
     
     
       14. A roof support assembly according to claim 6, wherein the hydraulic advance ram means of each advance mechanism is constituted by a pair of hydraulic advance rams each of which is pivotally attached to the slide piece of a respective guide rod. 
     
     
       15. A roof support assembly according to claim 14, wherein the hydraulic advance ram of each advance mechanism, that is lower down an inclined face, has a longer working stroke than the other, higher hydraulic advance ram of that advance mechanism. 
     
     
       16. A roof support assembly according to claim 15, wherein the lower guide rod of each advance mechanism is longer than the upper guide rod. 
     
     
       17. A roof support assembly according to claim 14, wherein at least one hydraulic advance ram of each advance mechanism is fastened to the associated floor girder by means of a longitudinally adjustable member.